Multi-position electrical switch



do 219 R. moon@ POSITION ELECTRICAL SWITCH MULTI Filed Oct. 24 3.956

INVENTOR wi @www nited States Patent MULTI-POSITION ELECTRICAL SWITCHRussell Brooks, Towson, Md., assignor to The Martin Company, acorporation of Maryland Application October 24, 1956, Serial No. 618,020

9 Claims. (Cl. 20G- 6) This invention relates to a multi-positionelectrical switch, and more particularly to a switch of the wobble disccontact type.

In many electrical systems it is desirable to provide a single switchwhich is capable of making and breaking a variety of differentelectrical circuits with extreme rapidity. In most circumstances inwhich such characteristics are desirable, it is also desirable for theswitch to be as compact as possible, and sealed in such a manner as toinsure against interferences with operation due' to the entrance intothe switch body of moisture, dust or other contaminating matter.Previous attempts to satisfy the need for such a switch have beenswitches which if suiciently compact and capable of a large enoughnumber of Contact `positions, could not be operated rapidly, did not4engage and disengage the Various contacts with detiniteness, and couldnot pass rigorous humidity tests.

In many instances, it is very important for a multiposition electricalswitch of this type to have definite operating characteristics in allpositions, for the switch operators attention may be concentrated onsomething other than the operation of a switch. As an example, theoperator may be watching a display upon a cathode ray tube, such as maybe used in conjunction with a radar set. In such an instance, it is mostimportant that the switch have distinct feel characteristics so that theoperator will be enabled to detect `the making or breaking of aparticular circuit, and to be cognizant at all times of the exactposition of the contacts of the switch. Existing switches of themulti-position type have been found to require high operating forceswith attendant slow speed operation, to` lack satisfactory feelcharacteristics, and generally to be somewhat limited in the manner inwhich the operating lever of the switch can be moved from one operatingposition to another. v

It is, therefore, a principal object of this invention to provide amulti-position electrical switch which enables a variety of electricalcontacts to be rapidly engaged and disengaged in a delinite, snap actionmanner.

It is another object of this invention to provide a multipositionelectrical switch which, because of the relatively small forces requiredto manipulate the operating lever of the switch, and otherconstructional advantages possesses very sensitive feel characteristics.

It is still another object of this invention to provide a multi-positionelectrical switch in which substantial force is exerted in engaging anddisengaging its various contacts, but in which the sensitivity of theoperating lever can be varied to meet individual needs.

It is a further object of this invention to provide a multipositionelectrical switch in which the operating lever can be rapidly moved fromone contact position to another without it being necessary each time forthe operating lever to be moved through a neutral point.

It is a still further object of this invention to provide amulti-position electrical switch which is compact, simple in design, andwhich is sealed so that it will operate yICC satisfactorily withoutelectrical failure under extreme environmental conditions, includinghigh humidity.

A multi-position electrical switch constructed according to thisinvention comprises a central distribution contact and at least threefixed electrical contacts arranged in a spaced array about thedistribution contact. The distribution contact has at least six flatside edges,'with alternate side edges aligned with the fixed electricalcontacts. A wobble disc is located upon the distribution contact, and isarranged to tilt upon any of the flat side edges. The wobble disc isequipped with a flange overlying and normally spaced from the fixedcontacts, and means are provided to selectively tilt the wobble discupon a at side edge to bring the flange into operative engagement withat least one of the fixed electrical contacts. The disc, when tiltingupon one of the alternate side edges that is aligned with an electricalcontact, is brought into operative engagement with only that contact,and when tilting upon a side edge intermediate two of the alternate sideedges is brought into operative engagement with two xed electricalcontacts.

An operating lever may be employed to move the wobble disc to thepositions desired, and the lever is equipped with a spring urged plungerthat is biased into iirm engagement with the wobble disc, thereby tobias the lever and wobble disc to a neutral position in which the wobbledisc is out of engagement with the fixed contacts. Because of thiswobble disc bias and tilt arrangement, the wobble disc has a definitesnap action as the operating lever is moved to and from each position.

A guide plate is preferably provided adjacent the operating lever, and anumber of lever-receiving recesses are provided in the guide plate. Thepositioning of the recesses is related to the positioning of the xedelectrical contacts, and are of a number equal to the number of thefixed contacts. While the operating lever is freely movable between itsvarious operating positions, the guide plate is nevertheless effectiveto stabilize the operating lever in certain operating positions, so thatthe wobble disc is stabilized in each operating position either by beingin engagement with two electrical contacts, o1' because the operatinglever is in engagement with a recess in the guide plate.

Further objects and advantages of this invention will be more readilyapparent from the following description, when read in connection withthe accompanying drawings in which:

Figure 1 is an elevational cross sectional view of the switch;

Figure 2 is a top plan view of the distribution contact;

Figure 3 is a side elevational view hof the distribution contact;

Figure 4 is a sectional view taken along line 4 4 of Figure 1; and

Figure 5 is a diagrammatic view showing the relation of the guide plateto the lixed contacts arrayed about the centrally disposed distributioncontact, and revealing symbolically the mannerv in which contact is madebetween the centrally disposed distribution contact and either a singlefixed contact, or simultaneously with two iixed contacts.

The switch according to this invention includes a distribution contact 5and fixed electrical contacts 1, 2, 3 and 4 placed in a spaced arrayabout the distribution contact. In the illustrated arrangement, thecontacts are preferably located on one end 7 of a hollow housing 7 thatmay be cylindrical in shape, and open at the other end. The housing 7,including end portion 7 is preferably made of plastic or othernon-conducting material, and the contacts are in sealed relation to thehousing.

A peripheral ange 8 is formed about the upper surface ofdistribution-contact5,and as illustrated in Figs. 2

through 4, f the JAper-ipheraliiange` 8- hasaenumberv of4 flat sideedges t. As revealed in Figure 4, alternate side edges 8' are placed inaligned relation with the ixed contact. points 1,2, 3v and4-,--^while"theside edges lintermediate the alternate side edgesare inalignment with points that would be midway between any twofixedcontacts. While fthe preferred Aembodiment shows eight side vedges andrfourfixed contact points, itis to-be understood that six side `edges`and threecontacts--points, or another even -number of-side edgesand'half asmany contact points :could be successfully employed -in`accordance with this invention.

- IA wobble Adisc 6 `is mounted upon the distribution consired. A lowerhub 9 is centrally provided on the lower ;surface=of WobblediscI-,` andthis hub titsv within a recess ISlocated inlthe upper-surfaceofdistributionfcontact 5.

This .insures thetcorrect positioning of lthe \wobble disc in thedesired location atop the distribution contact. 'The hub 9 is undercutYto a diameter suiciently'lesslthan'the 4inner diameterzof recessSQthatthe disc16can be 'freely `moved with respect to thedistributioncontact, into engagement with any of the tixedcontacts.

The wobble discm6 extends upwardly and' outwardly from its centralportion `insomewhatof a conical manyner, and'ont'the undersideof-theiperipheryA of the-disc Vis -a metallic contact .ring or'ange '10that extends entirely about the periphery, of the'dise .The iiangel10foverlies the tixed contacts 1' through 4 and isY normally spaced-therefrom, but as the ywobblediscis tilted, the `liangerl will -bemoved intoelectricalfengagementwith any contact, orinto simultaneousengagementwith-two adjacent contacts.

. An operating lever: v1S :is mounted 1in`housing 7 'directly abovewobble disc^6, sotthatthediscmaybemovedinto the desired positionof'engagernentrwithithe fixed contacts.

An enlarged or ball shaped portion 14 is provided on .the operatinglever adjacent theendfoflthe'levernearest lthe wobble disc 6. This'ball='shaped"'portion..isi rotatably mounted in ball socket; 28, which-islcreated betweenvball retainers 12 and 13. The ball retainers areclosely tted into the upper -or open end `of-the housingandan-encircling shoulder 27 is provided on the inner surface of theside oftheI housing' to..forma';support forthe'ball retainers. socket2S, and as it is moved in one direction, this-.causes a countermotion ofthe' lower extension'17 of theloperating lever, across the fulcrumformed by the ball shaped portion inball-socket 28. Therefore, `byappropriate movements of -the operating leverjthe wobble `disc may bemoved freely -intoanypositiondesired. An operating buttonl is -providedlon the 'upper endoftheoperating lever: 15,2'and1. thisl buttonismaintained infthe desired location by meansof-a suitable set screwt'l.

The surface of wobble disc 6 opposite the hub'-9 is provided with aconicalsoeket11,which maylbearcuate butfwhich ispreferablysubstantially` parabolicfasv shown. A `plunger 19 of hard plastic orother finsulating'mate'rial is slidably mounted in :a suitable= recess.inextension 17, and isbiased by` compression spring'lSrintofirm-engagement with v`socket 1-11. Because `of the spring Vbiasedplunger and its `interactionwith thersocketllfwhen 'the operating lever`is released, it willcenteras shown in Fig. 1 to' hold the wobble disc 6in the flat, centered-position in which it is out of engagement with allof the xed The lever is universally movable in ball contacts. When theoperating lever is manipulated to one Vaf-its "angular eperafingpesitions, the 'plunge `A19 'will ride up on the concave surface of theconical socket 11, and will cause the wobble disc to be tilted upon oneof the flat side edges 8 so that the tiange 10 will be brought intoengagement with one or more of the fixed contacts. At this time, aselectedvcircuitwill be completed to effect the desired operation.

It is to be noted that whenithe operating lever'has been moved to adeflected position, the spring 18 is compressed to a greater extent thanwhen the switch is in its centered position. This compression of thespring causes the wobbledisc'to `be heldagainstltheselected contact orcontacts with relatively high pressure, which insures good electricalcontact with a minimum chance of arcing. It is also to be noted thatwith this construction, a snap action of the disc is produced bothduring the making and the breaking of a circuit, due to the fact thatthe wobble disc will' tilt sharply ,upon a fiat-side edge 8 inonedirection or'the other as soon as'the line of force exerted byplunger 19 crosses the edge upon which the wobbledisc lis-tilting.

To insure stabilityl for'the switch when the operating lever 15 has beenmoved to bring the wobble disc'into 'engagement with a single fixedcontact, a guide plate -21 is'providedin "the upper portion of thehousing 7,'and an`aperture'22 is located in the central portion of theguide'pl'ateg through whichthe operating lever 15 extends. 'Theap'erture22 is formed in such a manner as to provide a numb'eroflever-receiving recesses 22', the Anumber of recesses ybeing dependentupon'the number of yfixed contacts, 'and'in' this Vinstance'being fourin number.

'These recesses ZZare placed in a definite orientation 'with Arespect'to'the fixed contacts, and inasmuch as the operatingleverIS moves in theopposite directionv to 'the directionof `the contact with whichthewobble'disc is making^"engagement, .the recess that corresponds to aparticular xed contactis located" away 'from that contact. In yotherwords, referring'to' Figf'S, if the operating lever 15 is movedintoanyofthe cardinal positions :A,.C, E or G, the'wobbledisc willbecaused'tot'ilt'into engagement with-fixed contacts"3,"4,"1, `or'"2,respectively.

Also `indicated on the guide plate"'21y are 'theiitrmediate positions B,D, F and H. When'the 'operating lever -has -been-rnovedto one Aof thesepositions,"the` wobble ydisc is caused to be Amovedintoengagerreirtwithtwo lixed cont-acts simultaneously. Y"A'study'of'Fig'S `will re- `v'ealthe various contact -relationshipsithat'canv'be obtained vby 'the use of the present switch. As an example,when theoperating lever "has Ybeen movediinto position I-Li the'wobble-disc V6 moves'so "asto bring contacts 2 fand 31intoelectricalengagement with the distribution contact-Tias is indicated -in -the4lower right-hand corner of Fig. 5.

The construction of the ywobble disc-contacty arrangementis such that bymaintaining his finger on the Voperating button--16,-'the operator cansense vthe position'of the wobble disc` at' all times. -Wherr theIoperating llever has been lrnovedto an intermediate'fposition `so-as tocause the wobble disc 6 to tilt'pon an intermediate edge 8',"the flange10 comestore'st upon two fixed contacts, thereby toform a tripodThe'biasof plufnger1'9 is suiiicient that thewobble disc willllite-moved to and from lthis tripodconiiguration with quite-abitofdeniteness, which is responsible for the factthatthe operator canfeel'tsuch movements of the `wobble disc. Thisvconstruction, inconjunction with the-'provision of the guide plate for guiding theoperating lever when it is desired to engage va single Contact makes itpossible for the operator to move theswitch into any and` all of thepositions desired without any substantial amount of concentration on theoperation being necessary. Furthermore, the operating lever need not bereturned tothe center or'restpositioneach time, for the switchcan-bemoved from' onel position to another, or-even'through Vall'eightpositions l'seriatim Awithoutit being necessary to cause the operatinglever to pass through the position indicated in Fig.' 1;

Since it is understood that different operators will have varyingdesires as to the sensitivity of the switch, according to this inventionthe operator may adjust the compression of spring 18 so that the wobbledisc will be caused to engage and disengage the fixed contacts with adesirable amount of force. To this end, a centrally disposed adjustmentscrew 20 is provided in the central portion of operating lever 15, andsince this screw is in operative relation to the upper portion of spring18, by adjustment of screw 20, the spring 18 may be adjusted to thedesired amount of compression.

Suitable sealing arrangements are provided so that the switch accordingto this invention will be environmentally free. As previously mentioned,the contacts in the bottom 7 are in sealed relation and ball retainer13, which rests upon shoulder 27 located around the interior of thehousing 7, is provided about its periphery with an Oring 31. Suitablegrooves or recesses are provided on the periphery of retainer 13 and onthe interior of the housing so that the O-ring can be seated verytightly. Further, a seal 26 is provided about the periphery of retainer12, and a cup shaped resilient seal or boot 23 is provided intermediateretainer 12 and guide plate 21. The central portion of boot 23 isprovided with an aperture to receive the operating lever 15, and theboot is preferably sealed to the lever, such as at point 24.

The guide plate 21 may be maintained in the desired position in theupper part of the housing by means of two or more screws (not shown)that extend radially inward through the cylindrical walls of the housingand threadedly engage suitable threaded holes provided on the peripheryof plate 21. Preferably these switch components are so arranged that thelower fiange 30 of boot 23 will be tightly compressed between the upperface of ball retainer 12 and the lower face of guide plate 21 at point25 to provide a good seal. In addition to sealing the operating leveragainst the entrance of moisture into the switch, the lboot 23 preventsundesirable rotation of the operating lever 15 about its axis, for theboot 23 would become wound up when such rotation tended to take place.

The ball socket 28 and the ball 14 are preferably provided with analuminum alloy hardcoat and lubricated by a suitable application ofmolybdenum disulfide or molybdenum disulfide in a resin binder. Thismethod of lubricating eliminates the need for any further lubricationduring the normal period of the usefulness of the switch.

To facilitate the attachment of an electrical conductor to thedistribution contact 5, a suitable fitting such as a screw 32 may -beprovided on the underside of this contact. through 4 preferably extendbelow the bottom 7 of the housing, and similar fittings are provided onthese lower portions so that all of the contacts of the switch can beelectrically connected to the circuitry in which the switch is to beused.

In the operation of this switch, the operator moves the button 16 in thedirection of one of the eight positions indicated on the guide plate.The motion of the operating lever causes a resulting countermotion ofthe extension 17 across the fulcrum formed by ball 14 rotating in ballsocket 28. This countermotion causes the plunger 19 to move away fromthe center of the conical socket 11, located in the upper portion ofwobble disc 6, and -to ride up on the concave surface of the socket.When the line of force passes the edge of peripheralfiange 8, the wobbledisc is caused to pivot or tilt upon a fiat edge 8 until the fiange orperipheral area 10 of the disc comes to rest on two fixed contacts in atripod arrangement or comes into engagement with a single contact. Theparticular engagement with the fixed contacts, of course,

The lower portions of the fixed contacts 1 f depends upon the positioninto which the operating lever is moved. When the wobble disc is movedinto engagement with a single fixed contact, Ibecause of the presence`of guide plate 21, one of the recesses 22 is available to stabilize theoperating lever 15, and this in turn causes the wobble disc to bestabilized in its tilting about the fiat edge 8' that is aligned with asingle contact.

This construction in which fiat undersurface 46 of the wobble discpivots upon the fiat sides 8 of the peripheral flange 8, in conjunctionwith the spring biased plunger arrangement provides a snap -action ofthe switch as it is moved into the position desired. When in anoperating position, the wobble disc 6 provides a good current pathbetween the distribution contact and the fixed contact or contactsengaged by the peripheral flange 10.

When the `button is released, the plunger 19 tends to return to thebottom of the concave socket 11, in which position the spring 18 is in aless compressed state. This causes the wobble disc to be snapped backinto the neutral position, with 4a minimum of arcing taking placebetween the peripheral flange and the fixed contact or contacts.

Modifications of the present invention will be apparent to those skilledin the art, but it will be understood that such modifications are withinthe true purposes and the scope of the following claims.

I claim:

l. A multi-position electrical switch comprising a distribution contact,at least three electrical contacts arranged in a spaced array about saiddistribution contact, said distribution contact having at least six fiatside edges, with alternate side edges laligned with said electricalcontacts, a wobble disc located upon said distribution contact andarranged to tilt upon any of said fiat side edges, said wobble dischaving a flange overlying and normally spaced from said electricalcontacts, and means to selectively tilt said wobble disc upon `a flatside edge to bring said fiange into operative engagement with at leastone of said electrical contacts, said disc when tilting upon one of saidalternate side edges in alignment with an electrical contact beinglbrought into operative engagement with only that contact, and whentilting upon a side edge intermediate two of said alternate side edges,being brought into operative engagement with two electrical contacts soas to provide three point support for said disc.

2. A snap action multi-position electrical switch comprising adistribution contact, at least three electrical contacts arranged in aspaced array about said distribution contact, said distribution contacthaving -at least six fiat side edges, with alternate side edges 'beingaligned with said electrical contacts, a wobble disc located upon saiddistribution contact and arranged to tilt upon any of said fiat sideedges, said wobble disc having a iiange overlying and normally spacedfrom said electrical contacts, means to selectively tilt said wobbledisc upon a fiat side edge to bring said flange into operativeengagement with at least one of said electrical contacts, said disc4when tilting upon one of said alternate side edges in alignment with anelectrical contact being brought into operative engagement with onlythat contact, and when tilting upon -a side edge intermediate two ofsaid alternate side edges, being brought into operative engagement withltwo electrical contacts, and means biasing said wobble disc to a neutralposition in which it is out of engagement with said fixed contacts,whereby said switch will have definite snap action as the wobble disc ismoved to and from each tilted position.

3. A multi-position electrical switch comprising a central distributioncontact having an upstanding peripheral flange with at least six iiatside edges spaced therearound, at least three fixed contacts arranged atspaced intervals about said distribution contact, alternate side edgesof said peripheral fiange being aligned with said fixed contacts, awobble disc supported by said peripheral fiange distinse v-and arrangedAto tilt upon any of said fiatside 'edges, said 'disc'havingl a'peripheral area overlying land I normally A:spaced f romsaid fixed`contacts', 'an 'operating' lever arranged fto' engage said disctoselectively tiltsaid disc 'upon :a 'flat side'n edge lof'saidid'ilstribution contact'sdas to "'bring' said'pe'ripheraliaifea int 'operative engagement 'with at least one of said fixed contacts, andaguide plate 'ad- "jacent said operating `llever,"saidguide'platefjhaving a :nu'r'nber of lever-receiving recesses therein,thposition- 'ing of said recesses being related` to"th po'sitioninghr"said Ifixed Acontacts and Abeing of' a"nu`rnber equal to the "number"of Ysa'id iixed contacts', said operating lever being freelyx movablebetween allj operating fpesitioneand'being stabilized 4by said1'g'uideplate vt/ henbeingpp reted .'jso as to cause sa'idwobble' disc totilt upon one of 'said 4'alternate' side edges, saidfdiscwhen tiltingupon a side "edge intermediatetwo of s`aid'alter`r'iateI side edgesbeing stabilized 'by engagement with "two orsaid fixed con- 4. A snapIaction multi-position electrical switch com- 'prising' acentral'distribution zcontact having 'an upstanding peripheral flangewith at A least six fiat side ed'ges spaced'therearund, at least threefixed contacts' arranged a t"spaced inte'rv'alsab'out said'distributioncontact, alterfrane sidev edges' of said priph-eral 'aange-'beingaligned with said fixed contacts, a wobble disc supported by saidperipheral fiange and arranged to tilt upon any 'of said fiatsideed'ges, said discfthaving'a' peripheral area overlying-and'norrnallyspaced from' said fixed contacts, an operatihgflever arrangedto'selectively tilt said disc upon ing a 'spring urged plunge( biasedinto frin'engagement with said wobble disc, saidlever and wobble discthereby 'being biased to va neutral position in which said wobble discis out of engagement'withsaid fixed cont-acts, and -a guide 'plateadjacent said loperating lever, said guide 'plate having a number ofAlever-receiving recesses therein,

'the positioning of 'said recesses being related to the posi- 'tioningof said fixed contacts and being of a number 1eq'ual `tof 'the numberofsa'id fixed cont-acts, said operating lever being freely movable'Abetween its various operating positions, and being stabilized bysaid'guide plate v'when being operated so' as to causesaid wobblediscwto tilt upon one of said .alternate side edges, said disc, whentilting upon 'aside' e'dge 'intermediate two of said alternate sideedges being Ist'abilied by"engagement with two 'of said fixed contacts.

V5. Themulti-p'osifidn electrical's'witch asvdefined in 4claiin 4 fi'n'whichmcans a'r'e provided fof modifying the force with vvh'ich saidplunger is'biased into engagement withsaidfwobble disc,'whereby thesensitivity of operation 'of said switch can be'altered.

6. nin i-fpo'sitio'n electrical switch comprising a housing,a'dis't'r'ibutin 'contactinounted insaid housing, said distribution'contact having 'at least six fiat side edges, at least'threee'lectricalcontacts mounted lin said housing and 'arranged in a spaced array aboutsaid distribution contact, alternate side edges ofsaid distribution.contact being aligned with said electricalpont'acts, a wobble discsupported 'by said distribution contact and arranged to tilt upon any ofsaid fiat side edges, said 'wobble disc having a lfiange overlying andnormally spaced 'from said l iixed contacts, and an operating,lever-projecting into s'id housing and mounted therein for universalangular movement, said lever being arranged to 'engage said disc4 so asto tilt it'uponone of said fiat side edges of said distribution contactto bring the fiange of said wobble "disc intoenig'agement with at leastone of said electrical contactsand aguideplete for said operating lever,said l `nber'oflever-receiving recesses thereinQtheY positioningl offsaid reoessesbeing related to "the positioning of said'electricalcontacts in said housling, 4and'b t'eingio'f number *equal to -thenumberof said electrical.'contacts,"said operating lever being Astabiliredbyfsid guide' platewhen said lever is beingoperated so astro' case'said:wobble discntoilt upon one of said alternate side edges, said disc whentilting upon a side edge'intermediate twomof said alternate side edgesbeing stabilized by engagement with two of said electrical contaCt5 l-lu 1.1-,

The'niulti-position electrical switch las defined in claim' 6 inwhichsealing means are provided between said guide plate and saidhousing, and surrounding .said operating lever'aty the location whereinit projects into said housing, lto prevent theentry of dust andmoisture. 8. The multi-'position electrical switch as defined in claimin which means are provided to prevent dislodgment of said wobblediscfrorn said distribution Contact.

9. AV snap action multi-position electrical switch cornprising ahousing, a central distribution contact disposed in said housing, said,distributioncontact havi'ng anupstanding peripheral flange Withiat leastsix fiat side edges spaced therearound, -at least `three fixed contactsmounted in saidhousing'and` arranged at spaced intervals :about saiddistribution contact, alternate side edges of said peripheral fiangelbeing aligned with said fixed contacts, a wobble discsupported by saidperipheral fiange'and arranged to tilt upon any lof saidflat sideedges,said disc having a conical socket centrally disposed on i'its uppersurface, and a peripheral area overlying and'normally spaced from saidfixed contacts, an operating lever disposed ina location directly abovesaid disc and arranged ,to selectively tiit said disc upon a fiat sideedge'of said ydistribution contact so as to bring said peripheral areainto operative engagement with vat least one of'said fixed contacts,said operating leveruhaving a spring urged plunger biased into firmengagement with said conical socket, s'aid lever and wobble disc therebybeing biased to a neutral position in whicth said wobble disc is out ofengagement with said fixed contacts, and a guide` plate adjacent saidoperating lever, said guide plate having a number of lever-receivingrecesses therein, the positioning of said recesses being related to thepositioning of said fixed contacts and being of a number equal to thenumber of said fixed contacts, said operating lever being freely movablebetween its various operating positions, said guide plate beingeffective to stabilize said operating lever when said wobble disc isbeing pivoted upon one of said alternate side edges, whereby said wobbledisc is stabilized in each operating position either by 'being inengagement with two electrical contacts, or by the operating lever beingin engagement with a recess in said guide plate, said switch, becauseIof said wobble disc bias and tilt arrangement, having a definite snapaction as the operating lever is moved to and from each position.

References Cited in the 'file of this patent UNrrnDsTATEs PATENTS

